Pi-hole with hassio & docker - DNS service not running, FTL service offline

I’m running pi-hole inside Hassio in a Docker container on my Synology NAS https://github.com/hassio-addons/addon-pi-hole and changed the Primary DNS settings on my Amplifi HD router to the Synology’s IP address and the Secondary DNS blank.

My setup is Internet <-> Virgin Superhub3 (modem mode) <-> Amplifi <-> Synology (all ethernet).

I installed pi-hole and can log into the web UI but it says that the DNS service is not running and the FTL service is offline.

The config file is:

{
  "update_lists_on_start": true,
  "ssl": true,
  "certfile": "fullchain.pem",
  "keyfile": "privkey.pem",
  "interface": "",
  "ipv6": true,
  "ipv4_address": "",
  "ipv6_address": "",
  "virtual_host": "pi-hole",
  "hosts": []
}

I’m a bit of a noob and would appreciate any pointers.

Thanks

I eventually got this working with a regular Docker installation by following these instructions https://mariushosting.com/how-to-install-pi-hole-on-your-synology-nas/